How They Make The Sausage

Elise Foley describes the process:

Who decides how to merge Baucus's conservative plan with its more liberal counterpart, to create the official Senate bill that will receive a vote in the full chamber? After the Finance committee votes on the plan, it's all up to the Senate leadership. According to congressional expert Norman Ornstein, Harry Reid is empowered to combine the Senate proposals using whatever method he considers most likely to attract a minimum of 51 votes and avoid a filibuster. Reid could designate a formal committee to mesh the bills, or he could assemble the final product in a closed room that includes the leadership and a few important senators.